Don't get a plasma if you plan on playing video games on it. They are the worst when it comes to leaving burns and ghost marks on your screen.
Incorrect. "burn in" was an issue on early plasma TVs, but its not an issue with good brand plasmas. I have a plasma, and game daily on it. No damage. The most there is will be a slight ghost on a solid color for til some other images run through the spot.
I have seen every piece of misinformation about plasma TVs in this thread now. The LCD companies certainly did the propaganda well.
I've seen it even in pricier sets, but then again I don't have the same motion blur problems that I've seen on other, more expensive LCDs than mine.
Strigoni is right about the small difference between 720 and 1080. If your not connected to an HD source like a blueray, PS3 or an HDDVR then your not really getting a 1080 anyway. But a 720 should still look pretty amazing in all but the cheapest models.